Kiwi plant named `Hort16A`

ABSTRACT

A new and distinct kiwi plant of the species Actinidia chinensis Planch. is described. The cultivar results from a controlled pollination using a male A. chinensis selection CK15 --  01 of unknown parentage, and a female A. chinensis selection CK01 --  01 --  01 --  01. Both named parents (CK15 --  01 and CK01 --  01 --  01 --  01) are unpatented cultivars. The new cultivar is distinguished by its short silky hair, protruding stylar end, golden flesh and sweet tropical taste.

BACKGROUND TO THE INVENTION

Kiwi plants in cultivation are deciduous vines of A.deliciosa. There are more than 50 species in the genus Actinidia originating in China and parts of Asia. The kiwi cultivar `Hayward`, developed in New Zealand, is the most widely grown cultivar because of its distinctive green flesh, good flavor and long storage life.

Less well known outside of mainland China is the species A. chinensis, closely related to A. deliciosa. Fruit can be as large as the kiwi, generally have much finer, softer hairs on the fruit skin, and can have either green or yellow flesh. Many Chinese prefer fruit of A. chinensis rather than the kiwi of commerce, considering the flavor to be superior. Like the kiwi, plants are dioecious, so male pollinizers are required as well as female plants to ensure fruit production.

A. chinensis plants grow vigorously in spring, and rapidly develop canes up to 4 m long if not managed correctly. Plants require a mild, warm-temperate climate, free from spring and early autumn frosts, and need well-drained soils to produce consistent heavy crops. Regular irrigation is necessary in dry spells. A. chinensis flowers in spring (mid-October to mid-November) in New Zealand. Harvest of A. chinensis fruit may occur between April and mid-May in New Zealand, depending on the selection and location of plantings.

SUMMARY OF THE INVENTION

The present invention relates to a new and distinctive kiwi plant having a generally ovoid shaped fruit which tapers towards the stylar end and which has soft, silky hair. More particularly, the new cultivar is designated `Hort16A` and is derived from a controlled pollination of A. chinensis CK15₋₋ 01, a male selection of unknown parentage, and A. chinensis female CK01₋₋ 01₋₋ 01. Both parents were derived from seedling plants grown from two introductions of seeds from China in 1981 and 1978 and are unpatented.

The new cultivar of kiwi was created in the course of a plant breeding program which was initiated during 1987 at Hort Research in Auckland, New Zealand. The cross made by Mark McNeilage in November 1987. Seed were sown in winter 1988 and 312 seedlings from this cross were planted out in the field at Te Puke Research Centre in spring,1988. The seedlings first fruited in May 1990 and `Hort16A` (breeding code CK01₋₋ 02₋₋ 01₋₋ 01) was selected, after storage and sensory evaluation in 1991 and 1992 by Russell Lowe and Hinga Marsh.

The new cultivar can be asexually reproduced as cuttings or by grafting or budding on to seedling or cutting-grown rootstocks of A. deliciosa or A. chinenis. Trial plantings on seedling rootstocks, established in 1992 at Te Puke, have shown that the unique combination of characteristics come true to form and are established and transmitted through succeeding asexual propagations.

`Hort16A` flowers four weeks ahead of the unpatented `Hayward` variety, so the usual pollinizers used for `Hayward` are ineffective as well as being of a different species and ploidy. Two new and unpatented early-flowering A. chinensis male pollinizers, designated Hortkiwi `Meteor` and Hortkiwi `Sparkler`, have been selected as males for use in new plantings of `Hort16A`.

BRIEF DESCRIPTION OF THE ILLUSTRATIONS

FIG. 1 shows typical fruit of the cultivar `Hort16A` on the vine

FIG. 2 shows typical fruit of the cultivar `Hort16A`

FIG. 3 shows `Hort16A` fruit in cross-section and profile

FIG. 4 shows `Hayward` fruit in cross-section and profile

FIG. 5 shows flowers of the cultivar `Hort16A`

FIG. 6 shows flowers of the cultivar `Hayward`

FIG. 7 shows mature leaves of `Hort16A`

FIG. 8 shows a mature leaf of `Hayward`

Photographs of fruit were taken after the normal harvest date. Colors may vary depending upon growing conditions under different climate, soil, and cultivation conditions and the fruit skin color may vary depending upon extent of exposure to direct sunlight.

COMPARISON TO CLOSEST CULTIVAR

The distinctive characteristics of this new kiwi cultivar, described in detail below, were observed in 1994 at Te Puke, New Zealand. The age of the plants was 3 years from the graft. Comparison `Hayward` vines were grown in another block on the same orchard.

The fruit of `Hort16A` is ovoid in shape and has a protruding distal end unlike `Hayward` which has a rounded distal end. `Hort16A` fruit are generally circular in cross-section although slightly flattened. `Hort16A` fruit has a much smaller core than `Hayward` and the flesh of ripe fruit is golden yellow whereas `Hayward` flesh is green. The hairs on the skin of the fruit of `Hort16A` are much finer, soft to the touch, and are very easily removed by rubbing or brushing to reveal a leathery, almost shiny skin. The skin color of `Hort16A` fruit is a yellow-brown in contrast to that of `Hayward` which is a medium brown color. `Hort16A` fruit have a higher dry matter content at harvest and are much sweeter tasting than `Hayward` fruit when ripe. While `Hort16A` fruit soften more rapidly than `Hayward` in coolstorage, fruit will stay at about 1 kg firmness for up to 3 months without further significant softening.

BOTANICAL DESCRIPTION OF THE PLANT

The new cultivar `Hort16A` is pistillate, with imperfect flowers, i.e. the flowers produce only sterile pollen and thus require a pollinizer for fruit production. Two specific A. chinensis pollinizers, named Hortkiwi `Meteor` and Hortkiwi `Sparkler`, have been developed for `Hort16A`. Characteristics of the new cultivar, in which it differs from the standard kiwi cultivar `Hayward`, include earlier flowering time, protruding stylar end on the fruit, silky easily-removed hairs on the skin, golden flesh when ripe, and yellow-brown colored skin.

    ______________________________________     TABLE OF CHARACTERISTICS     Horticultural terminology is used in accordance with revised UPOV     guidelines for kiwi.     Characters of comparison cultivar ` Hayward`  are noted opposite that     character in  brackets!  when significantly different.     `Hayward` plants were observed in a planting on the same orchard, but     not     the same plot.     All dimensions in millimeters unless otherwise stated, weights in grams.                  Hort16A     Hayward     ______________________________________     PLANT     Plant: sex expression                    female (flowers                    imperfect)     Plant: ploidy  diploid (2n = 2x = 58)                                   hexaploid!     Plant: vigor   strong         medium!     Young shoot: hairs                    present     Young shoot: density of hairs                    medium     Young shoot: type of hairs                    short          hirsute!     Young shoot: anthocyanin                    absent         medium!     coloration of growing tip     Young shoot: anthocyanin                    absent     coloration of leaf axil     STEM     Stem: coloration of leaf axil                    absent         weak!     Stem: diameter medium -                       Mean 11.0 mm                    (Range 8.3-13.3 mm)     Stem: dormant bud diameter                    6.9 mm (4.9-8.3 mm)     Stem: color on upper side of                    dark-brown     shoot     Stem: character of bark                    smooth         medium!     Stem: hairs    present     Stem: conspicuousness of                    conspicuous     lenticels     Stem: number of lenticels                    medium     Stem: color of lenticels                    brownish-white                                   greyish-white!     Stem: size of bud support                    medium     Stem: visibility of bud                    visible        almost buried!     (dormant canes)     Stem: number of hairs visible                     medium     on bud (dormant canes)     Stem: leaf scar                                   medium     LEAF (Mature)     Leaf: general shape of blade                    very broadly ovate     Leaf: length   170.3 mm                     (145-198 mm)     Leaf: width    186.3 mm                     (159-217 mm)     Leaf: petiole length                    166.8 mm                     (100-250 mm)     Leaf: shape of tip of blade                    cuspidate      mucronate!     Leaf: shape of base of blade                    cordate     Leaf: arrangement of leaf                    overlapping     bases     Leaf: puckering/blistering on                    weak           medium!     upper side of blade     Leaf: margin   ciliate     Leaf: green color of upper                    light-medium     side of blade     Leaf: glossiness of upper                    medium     surface of blade     Leaf: color of lower side of                    light green     blade     Leaf: glaucosity (lower side                     absent     of blade)     Leaf: hairs on petiole                    present     Leaf: density of hairs on                    medium     petiole     Leaf: anthocyanin coloration                    medium     on upper side of petiole     FLOWER     (Measurements are from a 20     flower sample)     Inflorescence: predominant                    one     number of flowers     Pedicel: length                    medium - 42.0 mm                    (29.9-49.20 mm)     Pedicel: hairs present     Pedicel: length of hairs                    very short     Flower: number of sepals                    >5     Flower: color of sepals                    pale green     Flower: diameter (terminal or                    large - 47.9 mm (42.3-     king flower when fully open)                    52.5 mm)     Flower: petal length                    23.1 mm                     (20.8-25.4 mm)     Flower: petal width                    17.7 mm                     (15.8-19.1 mm)     Flower: petal length/width                    1.31 mm     ratio           (1.14-1.45 mm)     Flower: mean number of                    8 (6-10)     petals per flower     Flower: number of flowers                    17 out of 20 flowers     with more than six petals     Flower: arrangement of petals                    overlapping     Flower: petal shoulder                    present     Flower: primary color of                    white     petals (when fully open)     Flower: type of coloration of                    uniform color over     petals         whole petal     Flower: style number                    30.85 (26-36)     Flower: attitude of styles                    erect          semi-erect!     Flower: curvature of styles                    straight       strongly                                  curved!     Flower: amount of hair on                    strongly expressed     ovary     FRUIT     (Measurements are from a 10     fruit sample)     Fruit: overall size                    large 98.3 g                     (43-176 g)     Fruit: length  79.1 mm                     (76.0-84.2 mm)     Fruit: width (max.)                    53.1 mm                     (55.4-48.1 mm)     Fruit: width (min.)                    49.1 mm                     (47.0-51.2 mm)     Fruit: core diameter (max.)                    13.1 mm                     (9.3-17 mm)     Fruit: core diameter (min.)                    4.9 mm                     (4.1-6.1 mm)     Fruit: locule number                    34.5 (26-37)     Fruit: peduncle length                    48.3 mm                     (44.7-50.3 mm)     Fruit: peduncle width                    3.57 mm                     (3.22-4.28 mm)     Fruit: general shape                    ovoid          cylindrical!     Fruit: cross-section at median                    elliptic     Fruit: general shape of stylar                    protruding     flat!     end     Fruit: shape of shoulder on                    rounded     stalk end     Fruit: skin color at harvest                    yellow-brown   brown!     (fruit still hard)     Fruit: skin color change                    absent     during ripening     Fruit: skin color at maturity                    yellow-brown   brown!     for consumption     Fruit: hairs   present     Fruit: density of hairs                    medium     Fruit: type of hair                    pubescent      hirsute!     Fruit: hair length                    short          medium!     Fruit: concentration of hairs                    uniform     Fruit: adherence of hairs to                    weak           strong!     skin (when rubbed)     Fruit: core diameter (at                    small          large!     largest diameter)     Fruit: core shape (in cross                    elliptical     section)     Fruit: core woody spike                    present     Fruit: prominence of core                    weak           medium!     woody spike     Fruit: outer pericarp color at                    golden yellow  green!     maturity for consumption     Fruit: inner pericarp color                    brownish-yellow                                   green!     (locules) at maturity for     consumption     Fruit: core color at maturity                    white          greenish white!     Fruit: sweetness (Brix level)                    15.6% (14.4-17.0%)     at maturity for consumption     Fruit: Vitamin C content                    medium (125 mg/l00 g                    fresh weight)     Fruit: seed color at maturity                    dark brown     Fruit: seed color when dry                    brown     EVENTS (at Te Puke,     New Zealand)     Time of vegetative budbreak                    late August to first                    week of September     Time of beginning of                    late October to first     flowering      week of November     Time of maturity for harvest                     first-second week of     (at 10.0% SSC) May     ______________________________________

HORTICULTURAL CHARACTERISTICS

Details below relate to observations made on plants growing at Te Puke Research Centre, New Zealand. These plants were grafted on to A. deliciosa seedling rootstocks.

`Hort16A` vines can be grown on the same rootstocks as can `Hayward`. Rootstocks currently being used in New Zealand include A.deliciosa seedlings, `Hayward` rooted cuttings and Hortkiwi `Kaimai`.

Cropping: young vines of `Hort16A` carry higher yields than `Hayward` when plants of equivalent ages are compared, although at maturity, yields are likely to be similar. The storage life of `Hort16A` fruit is about 75% of that of `Hayward` fruit under a coolstorage temperature of 0° C. `Hort16A` fruit soften in coolstore more rapidly than `Hayward` fruit initially, but will hold at a ready to eat firmness of about 1 kg for over two months after the initial softening period.

OTHER DATA

Fruit size: Data from a random harvest of 1940 fruit which were graded to measure fruit size in May 1995. Individual fruit weights collected electronically from the grader.

Mean fruit weight: 98.3 g.

Minimum.--43 g.

Maximum.--176 g.

Standard error of the mean (SEM): 0.574.

    ______________________________________     COLOR CHART RHS Colour Chart, the Royal Horticultural     Society, London 1966.     ______________________________________     Flesh Color at maturity:     Outer pericarp     Hort16A       12C-12B      Hayward 138B-138C!     Inner pericarp     Hort16A       162A-162C     Fruit core at harvest:     Hort16A       159C         Hayward 155A!     Seed color (in flesh):                   200A     Seed color (dry seed):                   200D     Fruit skin at maturity:                   combination of     Hort16A        199A plus 161A     Leaf color:     mature leaf after petal fall     Upper side of leaf     Hort16A       146A         Hayward 147A!     Lower side of leaf     Hort16A       147B         Hayward 147C!     Flower petals:     main body of petal                   155D     Plant stem:     exposed side  200B-200C-165A                                Hayward 147C!     ______________________________________ 

We claim:
 1. A new and distinct kiwi plant of the species A. chinensis substantially as described and illustrated, characterized by yellow flesh with a sweet, tropical taste, ovoid fruit shape with a protruding stylar end, and yellow brown skin with soft fine hairs. 